Backup Cameras and Warning Radars for Blind Spot Monitoring Systems

Blind spot monitoring and alert systems have become standard configurations in vehicles, particularly in heavy-duty trucks. Some regions have enacted regulations that mandate blind spot monitoring for heavy trucks. This article primarily introduces the design, device selection, blind spot monitoring calibration methods, and key image processing technologies of blind spot monitoring systems for heavy trucks.

The blind spot in heavy trucks refers to the area where the driver's vision is obstructed due to the vehicle's large height and length, both when stationary and during movement. When other vehicles, pedestrians, or obstacles are within this blind spot, drivers with limited visibility may struggle to make correct judgments or decisions, potentially resulting in severe accidents. Hence, eliminating blind spots in heavy trucks is an effective method to address such issues.

01 System Solutions

This system collects images from multiple cameras and stitches them together to form a 360-degree panoramic image. This allows drivers to actively understand the surrounding environment of the vehicle through the display system screen. Ultrasonic radars detect pedestrians and obstacles in the left, right, and rear blind spots, alerting the driver through sound or flashing images when danger is detected. This enhances the driver's passive awareness of the vehicle's blind spots, thereby improving road safety.

To obtain panoramic images, front, left, right, and rear cameras are strategically placed based on the size of the heavy truck to capture images.

02 Major Device

Cameras come in high-definition and standard versions. Standard cameras use CVBS analog signal transmission with inferior display quality. High-definition cameras use AHD or LVDS transmission methods. Blind spot monitoring generally opts for the AHD high-definition transmission mode. Cameras are categorized as regular or wide-angle based on their field of view.

Regular cameras have a field of view less than 90 degrees, while wide-angle cameras have a field of view greater than 120 degrees. Heavy trucks require wide-angle lenses to meet panoramic imaging requirements.

03 Image Processing

Images captured directly by wide-angle lenses may have linear geometric distortion that needs correction. Distortion is rectified using chessboard calibration technology by transforming coordinates to restore the image.

The determination of image position and the use of stitching algorithms are employed to seamlessly merge images using a weighted average method, achieving smooth transitions in the 360-degree panoramic image.

04 System Function Implementation

• Driving Mode: Provides a 360-degree panoramic image and alerts the driver through images and sounds when pedestrians or obstacles are detected around the vehicle. Displays the main areas of concern using side and front cameras.

• Reversing Mode: Displays the rear blind spot through cameras and alerts the driver using radar.

• Turning Mode: Displays blind spots during turns through cameras and alerts the driver using radar.

• High-Speed Mode: Alerts the driver through radar and signals when vehicles are overtaking or during active overtaking, especially at high speeds.

The 360-degree panoramic monitoring and radar-assisted warning system in heavy trucks provide comprehensive information about the vehicle's surroundings, alerting drivers promptly and enhancing road safety.